Agency retainers versus advertising spend: where a dental marketing budget actually goes
How agency fees and advertising spend relate, why a fixed fee takes a large share of a small budget, the main fee models and their incentives, and how VAT changes the comparison for a dental practice.
Two lines, two different jobs
Every paid marketing budget has two parts. Advertising spend goes to Google, Meta or another platform and buys the clicks or impressions. The retainer or management fee pays someone to decide where that spend goes and to improve it. Spend is variable: the platforms treat a daily budget as an average or a weekly target, not a fixed charge [1] [2]. The fee is usually fixed.
Quotes often blur the two. Before comparing suppliers, write both lines down separately for each one, along with setup costs and VAT. The costs guide covers the full list.
How much of the budget the fee takes
A fixed fee takes a much larger share of a small budget. One supplier publishes monthly programmes starting at £995 plus VAT, with advertising spend separate [3]. Holding that fee constant, the share of the total that goes on management changes like this:
| Monthly ad spend | Total with fee | Share going to the fee |
|---|---|---|
| £1,000 | £1,995 | 50% |
| £2,500 | £3,495 | 28% |
| £5,000 | £5,995 | 17% |
| £10,000 | £10,995 | 9% |
Neither end is wrong in itself. A high fee share can be worth it if the work also fixes the website, tracking or enquiry handling. But if the fee is mostly for managing the ads, ask whether the spend is large enough for that management to pay for itself.
Fee models and their incentives
| Model | How it works | What to watch |
|---|---|---|
| Flat retainer | Same fee each month | What exactly is included, and what costs extra |
| Percentage of spend | Fee rises with ad spend | The supplier earns more when you spend more |
| Flat fee plus percentage | A base fee and a share of spend above a threshold | Where the threshold sits |
| Per lead | A price per enquiry | The definition of a lead, in writing |
A useful question for any model: "What would make you recommend spending less?" A supplier who can answer it clearly is thinking about your cost per patient, not their fee.
VAT treats the two lines differently
Dental care by registered professionals is generally exempt from VAT [4], and a business making exempt supplies normally cannot recover the VAT on related costs, subject to a de minimis test [5]. So VAT on a UK agency's fee is usually a real cost for a practice. Advertising spend billed by the platforms may be handled differently, through the reverse charge. The VAT section of the costs guide sets out both, with sources. Ask your accountant how much of each your practice can reclaim.
Checks before you agree a split
- Are fee and ad spend separate lines on the proposal and on every invoice?
- Is ad spend billed to the practice directly by the platform, so you can see it?
- If the fee is a percentage of spend, is there a cap?
- Does the fee cover only the ads, or also landing pages, tracking and enquiry handling?
- Is everything quoted with and without VAT?
To see how a given split turns into cost per started patient, use the acquisition cost calculator.
Sources
- Google Ads Help, About average daily budgets. Accessed 1 November 2026.
- Meta Business Help Centre, About daily budgets. Accessed 1 November 2026.
- Clinic Grower, Dental Marketing Agency UK. Accessed 1 November 2026.
- HM Revenue and Customs, GOV.UK, Health professionals and pharmaceutical products (VAT Notice 701/57). Accessed 1 November 2026.
- HM Revenue and Customs, GOV.UK, Partial exemption (VAT Notice 706). Accessed 1 November 2026.